当使用xib,并使用了AutoLayout之后,当需要适配机型时,或者手动更改视图的frame的时候,就需要修改约束啦.其实很简单的.
1.首先从xib中吧改变的约束拖到view上或者ViewController上
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *topLayout;
//机型封装到单例中 全局都可以使用
if (CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size)) {
return UIScreenSizeType_640x960;
}
else if(CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size)){
return UIScreenSizeType_640x1136;
}else if(CGSizeEqualToSize(CGSizeMake(750, 1334), [[UIScreen mainScreen] currentMode].size)){
return UIScreenSizeType_750x1334;
}else if(CGSizeEqualToSize(CGSizeMake(1242, 2208), [[UIScreen mainScreen] currentMode].size)){
return UIScreenSizeType_1242x2208;
}
return UIScreenSizeType_000x000;}
if([UIScreen currentScreenSizeType] == UIScreenSizeType_640x960){
_topLayout.constant = 40;
}else if([UIScreen currentScreenSizeType] == UIScreenSizeType_640x1136){
_topLayout.constant = 40;
}else if([UIScreen currentScreenSizeType] == UIScreenSizeType_750x1334){
_topLayout.constant = 40;
}else if([UIScreen currentScreenSizeType] == UIScreenSizeType_1242x2208){
_topLayout.constant = 40;
}
2.还可以为控件自定义一个约束
NSLayoutConstraint *myConstraint =[NSLayoutConstraint
constraintWithItem:iSinaButton //子试图
attribute:NSLayoutAttributeCenterX //子试图的约束属性
relatedBy:NSLayoutRelationEqual //属性间的关系
toItem:self.view//相对于父试图
attribute:NSLayoutAttributeCenterX//父试图的约束属性
multiplier:1.0
constant:0.0];// 固定距离
[self.view addConstraint: myConstraint];//为iSinaButton重新添加一个约束
